Already during his work on his PhD thesis Hawking became interested in black holes and their role in the creation of the universe. That's why his words on depression and the black hole metaphor we are all familiar with seems so beautiful and true to me:

“The message of this lecture is that black holes ain't as black as they are painted. They are not the eternal prisons they were once thought.Things can get out of a black hole both on the outside and possibly to another universe. So if you feel you are in a black hole, don't give up – there's a way out.”